package server

import (
	"bytes"
	"encoding/base64"
	"io"
	"net"
	"testing"
	"time"

	"github.com/x-grk/longpolling-remote-access/internal/proto"
)

// An http-lp download the agent has finished (its last chunk, then the end)
// reaches the browser whole: the session closing does not cut off what is
// still queued for it.
func TestForwardHTTPDrainsAfterClose(t *testing.T) {
	hub := NewHub()
	m := &forwardManager{hub: hub}
	user, host := net.Pipe()
	go m.bridgeHTTP(ForwardRule{AgentID: "a1", ClientPort: 80, Proto: "http"}, host)

	var sess *Session
	for i := 0; i < 100 && sess == nil; i++ {
		hub.mu.Lock()
		for _, s := range hub.sessions {
			sess = s
		}
		hub.mu.Unlock()
		time.Sleep(10 * time.Millisecond)
	}
	if sess == nil {
		t.Fatal("no session")
	}
	want := bytes.Repeat([]byte("0123456789abcdef"), 4096) // 64 KiB in 64 chunks
	go func() {
		for i := 0; i < len(want); i += 1024 {
			sess.PushOut(proto.OutMessage{Data: base64.StdEncoding.EncodeToString(want[i : i+1024])})
		}
		sess.PushOut(proto.OutMessage{Exit: true})
		sess.close() // as the server does on the agent's end of stream
	}()
	time.Sleep(50 * time.Millisecond) // all of it queued, the session closed, before the browser reads
	_ = user.SetReadDeadline(time.Now().Add(5 * time.Second))
	got, _ := io.ReadAll(user)
	if !bytes.Equal(got, want) {
		t.Fatalf("got %d of %d bytes", len(got), len(want))
	}
}